I have Arlo cameras (as documented somewhere about, they were Netgear but have been spun off as a separate company). I've been happy with them – they're basic (a range of models are available) but are positioned well-enough that they'll grab a face (for instance the driveway mounted one will trigger the porch, so I get to see people come and go and get a recognizable face-grab from the porch cam). The same with the back garden, it'll trigger if spots anyone (or a giant spider) and activate the ones covering the back and patio doors. As Ham says, if you need long-distance identification, you need higher than 1080p resolution and probably a fully-wired system or very good wifi.
They're battery-powered, so easy to install, though the batteries, of course, require periodic replacement (the full-fat lithium batteries last several months, I have some rechargeable ones, which last a couple). They have motion-detection and better-than-expected night vision (don't expect long-range through). They run on their own wifi network (there's an Arlo router that needs wired access to your router, though if I recall, there's a newer version that's will connect wirelessly). The wifi signal is good, it reaches the bottom of the garden. The basic subscription package is free (supports up to five cameras and a week of storage). As ever, they're dependent on an internet connection, so if someone was really savvy they'd sever the phone line, there's no in-device storage on my model, but then they'd probably just nick the device).
My main concern was that it would be one of those devices that require the occasional motivational restart, and a 'device offline' is not what you want when you're several thousand miles away, but it's never needed it. One of the cameras went a bit dud and developed a red tinge (presumably the IR filter stuck on) – it was always like that but stopped recovering after percussive maintenance, they replaced it when I got around to asking.
All runs via the Web or a phone app that does what you'd expect, you can set schedules, zones etc. and vary sensitivity, record time, alerts, etc.
We used to have a proper system but it got ripped out during the refurbishment and not put back, so we just left the ringer on the front. For about £500 I'm happy with it and it gives us peace-of-mind when we're out. Ultimately, no matter how good your system, I suspect the main challenge will be getting the police interested. Hopefully it never comes to that, statistically, it's unlikely you'll be burgled.
